Highwall mining is generally a method of mining whereby a remotely controlled continuous miner is positioned in a shaft to mine or cut ore from ore-bearing strata at a face area. The harvested ore is then transported to a bench area outside the shaft. Since the shaft is only wide enough to accommodate the miner and ore removal machinery, any machinery sent into the shaft cannot be turned around.
One method commonly used to transport ore from the continuous miner to an area outside the mine shaft is a winch-operated system. Winch-operated highwall mining systems commonly use a sled to transport the ore from the continuous miner to the bench area. A winch-operated highwall mining system is depicted in commonly owned U.S. Pat. No. 7,594,702, the entire contents of which are incorporated herein by reference thereto.
Operation of the winch-operated highwall mining system includes first pulling the empty sled to the continuous miner, holding the sled in position while the sled is filled by the continuous miner, and then pulling the sled away from the continuous miner to the bench area where it is unloaded.
The productivity of the aforementioned winch-operated highwall mining system is severely restricted by the usable load area of the sled. Increasing the sled length does not result in an increase in the productivity as the loadable area of the sled is limited to the load-distribution reach of the continuous miner. Thus, if a highwall mining sled is increased in length, it will not lead to an increase in productivity as the portion of the sled beyond the load-distribution reach will be unreachable by the continuous miner. As a consequence of the winch cabling to control the sled, a sled cannot be turned around in a winch-operated highwall mining system. Thus, it is not possible to turn a sled around within the highwall mine shaft in order to load the opposite end of the sled.
What is needed therefore is a device for improving the productivity of a winch-operated highwall mining system while avoiding the limitation imposed by the load-distribution reach of the continuous miner.